Initial BPF code.
Add iterator and reader.  Still won't work.
Merge.
Add iterator and reader.  Still won't work.
Remove getSchemaRef().
Fix BpfSeqIterator after merge.
Fill out bpf reader.  Ready to test.
Make things start to run.
Fix metadata read.
Fix string streaming.
Add test output.
Merge branch 'bpf' of https://github.com/abellgithub/PDAL into bpf

Conflicts:
	include/pdal/BoStream.hpp
	src/drivers/bpf/BpfHeader.cpp
	src/drivers/bpf/BpfHeader.hpp
	src/drivers/bpf/BpfReader.cpp
	src/drivers/bpf/BpfReader.hpp
	src/drivers/bpf/BpfSeqIterator.cpp
	src/drivers/bpf/BpfSeqIterator.hpp